Rice Research and Development Institute, Bathalagoda, Ibbagamuwa, LK

S. D. S. S. Sooriyapathirana

University of Peradeniya, LK

About S. D. S. S.

Abstract

Phosphorus deficiency (PD) is a limiting factor in rice farming and hence PD tolerant varieties are essential. The PD tolerant quantitative trait loci (QTL) have been identified using the rice landraces Kasalath and Nipponbare. However, PD tolerant Sri Lankan rice landraces or varieties have not been used for QTL mapping. It is important to study the genetics of the PD tolerance associated traits of the locally grown rice genotypes before mapping QTL. Thus, aim of this study was to unravel the genetics of PD tolerant associated traits in segregating progenies generated by crossing PD tolerant and sensitive rice genotypes. Four F2 progenies (H-4 × Bg 352, Suduheenati × Bg 352, Mas × Bg 352 and Suduheenati × Bg 357) had been created by crossing PD sensitive genotype Bg 352 with PD tolerant genotypes H-4, Suduheenati and Mas and PD sensitive genotype Bg 357 with PD tolerant genotype Suduheenati, respectively. The F2 seeds from each cross along with the parents were grown in a greenhouse using a P deficient soil. The growth and quantitative colour parameters were measured at flowering stage. The normality, broad sense heritability and heterosis were calculated for each trait. Goodness of fit tests were conducted for colour metrics considering the common epistatic dihybrid ratios. The growth parameters were normally distributed with higher heritability indicating a potential basis for QTL mapping. The colour metrics were not normally distributed and fitting into the epistatic ratios 9:3:4, 9:6:1, 10:3:3 or 12:3:1 implying that they should be controlled by major genes. All the studied traits showed higher heritability estimates. According to this information, it would be logical to map QTL for growth parameters and colour variation occurred due to PD.